The present invention relates to a fluidity determination method of a packed fluid and a device used in the fluidity determination method. More specifically, the present invention relates to a method for determining whether the fluidity of the packed fluid is high or low, whether the packed fluid is in a solid or liquid state, and whether the packed fluid is defective or non-effective, with high speed and without breaking or opening a pack, and a device used in this method.
In the food industry, fluids packed in various kinds of packs are sometimes used. When the packed fluids are manufactured, there is a case that the fluid having fluidity is filled with the pack, the fluidity of the fluid is changed, and the final product is completed.
For example, when desserts containing gelling agents such as a jelly are manufactured, a jelly raw material in a liquid state which is heated at high temperatures is packed, the fluidity thereof is gradually decreased by cooling using a refrigerator, and thereby the fluid is finally coagulated.
Moreover, xe2x80x9cfluidxe2x80x9d in the present specification means materials in a solid state having no fluidity, in addition to materials in a liquid state having fluidity. Therefore, a change of a fluid from a liquid state into a solid state or from a solid state into a liquid state is considered as a kind of fluidity change.
In the field of manufacturing packed fluid, the fluidity of the packed fluid is often strictly determined for production control.
For example, when the desserts containing gelling agents are shipped, if they are not sufficiently coagulated, and defective products are shipped, the trust of the consumers may be lost. Therefore, it is necessary to determine whether the products are defective or non-defective based on the fluidity level of the products.
As explained above, fluidity determination of the packed fluid has been important. In particular, in order to control production, a large scale factory is desired in which the products are continuously manufactured using transport lines such as a conveyor belt to determine the fluidity of some, preferably all, the packed products with high speed and without breaking or opening the pack. Moreover, it is also desired to always maintain the same level of accuracy in determining the fluidity when the environment changes due to a turn of seasons or when the environmental temperature changes due to a halt of machine operations in the factory.
For example, the following fluidity determination methods (I) to (IV) have been known in the food industry.
(I) a fluidity determination method in which a packed fluid is vibrated (Japanese Unexamined Patent Applications, First Publication Nos. Hei 02-236141 and Hei 10-033114);
(II) a fluidity determination method in which an agitation torque is measured when a liquid raw material of the fluid is agitated (Japanese Unexamined Patent Application, First Publication No. Hei 03-039061);
(III) a fluidity determination method in which the temperature, the electrical conductivity, etc. of a fluid are directly measured (Japanese Unexamined Patent Applications, First Publication Nos. Sho 59-217162 and Sho 62-040246, and Japanese Language Publication (Kohyo) Hei 03-503449 corresponding to PCT Patent Application); and
(IV) a fluidity determination method in which the temperature of a fluid is measured without contact using a non-contact type temperature sensor (Japanese Unexamined Patent Application, First Publication No. Sho 61-032387).
However, a device for vibrating the pack is needed in the fluidity determination method (I); therefore, the entire device is complicated and large. There are problems with the fluidity determination method (I) in that the costs of investment and running increase, and furthermore system maintenance management is complicated. Moreover, time is required for the determination process; therefore, the fluidity determination method (I) is unsuitable for a continuous determination of the fluidity of the packed fluids on a continuous basis.
Agitation vanes are inserted into the fluid stored in a tank in the fluidity determination method (II); therefore, the fluidity determination method (II) cannot be used for packed fluids.
A sensor is directly inserted into the fluid or in thermal contact with the fluid in the fluidity determination method (III); therefore, it is difficult to carry out this method without breaking or opening the pack when the product is packed. Moreover, time is required for the determination process; therefore, the fluidity determination method (III) is unsuitable for production control in a large scale factory. Furthermore, heat, electricity, etc. are applied to the fluids; therefore, there is a possibility that the fluid will be denatured. The fluidity determination method (III) is unsuitable for determination of all products.
In the fluidity determination method (IV), a non-contact type temperature sensor is arranged in a heating device, an aluminum film covering an opening portion of the pack is covered with a synthetic resin film, and the heat conditions of the fluid are adjusted while the temperature of the synthetic resin film is measured without contacting the fluid. In the method (IV), the amount of heat applied to the fluid in the heating step is measured and adjusted. It is difficult to determine the fluidity of the fluid other than during the heating step; therefore, the fluidity determination method (IV) is unsuitable for production control in a large scale factory.
Moreover, in general, these fluidity determination methods (I) to (IV) are easily influenced by the temperature variation due to a turn of seasons and a halt of machine operations in the factory. Therefore, these fluidity determination methods (I) to (IV) cannot always determine the fluidity with a stable accuracy. In view of reliability, these methods are not suitable for production control in a factory.
As stated above, a simple fluidity determination method of packed fluids without breaking or opening the pack, in particular, which can be used on a continuous type large scale manufacture line, has not been established. Therefore, in the past, a method in which a sample of the packed fluid is periodically taken, opened, and the fluidity is determined has been chiefly used. The packed fluid used in this method must be discarded after determination.
It is an object of the present invention to provide a determination method for the fluidity of the packed fluid, which does not determine the fluidity of the sample packed fluids and which can determine the fluidity of all the packed fluid, without breaking and opening the pack and which have high speed. In addition, the determination method can determine the fluidity of the fluid with high accuracy, independent of the environment around the fluid. Furthermore, the structure of the use device is simple, and the costs of investment and running for the device are reduced.
The another object of the present invention is to provide a determination device for performing the determination method.
The first aspect of the present invention to be solved the problems is a determination method of the packed fluid comprising the steps of locating at least two measurement points on the surface of the pack, measuring the surface temperature of the pack at the located measurement points, and determining the fluidity of the fluid based on the measured surface temperature.
Moreover, the preferred embodiments of the first aspect of the present invention are the fluidity of the fluid is determined based on the difference between the surface temperatures of the pack at the two measurement points;
whether the fluidity of the fluid is in desired conditions is determined by comparing the difference between the surface temperatures with a predetermined standard value, and determining whether the fluidity of the fluid is in desired conditions based on whether the difference between the surface temperatures is larger than the standard value;
whether the fluidity of the fluid is in a solid or liquid state is determined by setting the standard value between the surface temperature difference of the fluid in a solid state and the surface temperature difference of the fluid in a liquid state, and determining whether the fluid is in a liquid or solid state based on whether the surface temperature difference is larger than the standard value;
the measurement points include a first measurement point located on the approximate center position of the side of the pack;
the measurement points include a second measurement point located above the first measurement point, other than the first measurement point;
the measurement of the surface temperature of the pack is performed under conditions in which there is a difference between the temperature of the packed fluid and the environmental temperature; and
the measurement of the surface temperature of the pack is performed using a non-contact type temperature sensor.
The second aspect of the present invention to be solved the problems is a determination device for determining a fluidity of a packed fluid comprising at least (A-1) a non-contact type temperature sensor for measuring a surface temperature at a plurality of measurement points located at the different positions on the surface of the pack; and (A-2) an arithmetic means electrically connected with the non-contact type temperature sensor, which calculates a surface temperature difference at the two measurement points located at the different positions of the pack.
Moreover, the preferred embodiments of the second aspect of the present invention are the device further comprises (A-3) a defective product determination signal output means which compares the surface temperature difference calculated by the arithmetic means (A-2) with a predetermined standard value, and outputs the compared result as a defective product determination signal; and
the device further comprises at least (A-4) a transport means for transporting the packed fluid after the measurement of the surface temperature of the pack by the non-contact type temperature sensor (A-1); and (A-5) a defective product discarding means for discarding the packed fluid transported by the transporting means (A-4) from a transporting line, in response to the defective product determination signal output from the defective product determination signal output means (A-3).